Educational Inequalities in Obesity among Mexican Women: Time-Trends from 1988 to 2012

BackgroundObesity is one of the leading causes of global morbidity and mortality. Trends in educational inequalities in obesity prevalence among Mexican women have not been analysed systematically to date.MethodsData came from four nationally representative surveys (1988, 1999, 2006, and 2012) of a total of 51 220 non-pregnant women aged 20 to 49. Weight and height were measured during home visits. Education level (higher education, high school, secondary, primary or less) was self-reported. We analysed trends in relative and absolute educational inequalities in obesity prevalence separately for urban and rural areas.ResultsNationally, age-standardised obesity prevalence increased from 9.3% to 33.7% over 25 years to 2012. Obesity prevalence was inversely associated with education level in urban areas at all survey waves. In rural areas, obesity prevalence increased markedly but there was no gradient with education level at any survey. The relative index of inequality in urban areas declined over the period (2.87 (95%CI: 1.94, 4.25) in 1988, 1.55 (95%CI: 1.33, 1.80) in 2012, trend pConclusionsThe expected inverse association between education and obesity was observed in urban areas of Mexico. The declining trend in relative educational inequalities in obesity was due to a greater increase in obesity prevalence among higher educated women. In rural areas there was no social gradient in the association between education level and obesity across the four surveys.

背景 肥胖是全球发病与死亡的主要诱因之一。截至目前，针对墨西哥女性肥胖患病率的教育不平等趋势，尚未有系统性的分析研究。

方法 本研究数据源自四项具有全国代表性调查（nationally representative surveys）（1988年、1999年、2006年及2012年），共纳入51220名年龄在20至49岁之间的非妊娠女性。研究人员在家庭访视期间测量了受试者的身高与体重，教育水平（高等教育、高中、中等教育、小学及以下）由受试者自行报告。本研究分别针对城镇与农村地区，分析了肥胖患病率的相对与绝对教育不平等趋势。

结果 全国范围内，经年龄标化（age-standardised）后的肥胖患病率在1988至2012年的25年间从9.3%升至33.7%。在所有调查周期中，城镇地区的肥胖患病率均与教育水平呈负相关。农村地区的肥胖患病率虽显著上升，但在各次调查中均未呈现出与教育水平相关的梯度差异。此期间城镇地区的相对不平等指数（relative index of inequality）呈下降趋势（1988年为2.87，95%置信区间（95%CI）：1.94~4.25；2012年为1.55，95%置信区间（95%CI）：1.33~1.80，趋势检验P值，原文此处内容不完整）。

结论 墨西哥城镇地区呈现出预期的教育水平与肥胖负相关关联。肥胖相关相对教育不平等的下降趋势，源于高教育水平女性群体的肥胖患病率增幅更为显著。而在四次调查周期内，农村地区的教育水平与肥胖关联均未呈现社会梯度差异。